Improvement in compositions for printing and copying inks



UNITED STATES PATENT OFFICE.

JOHN UN DERWOOD AND FREDERIO V. BURT, OF LONDON, ENGLAND, ASSIGN- ORS TO VVALDO MAYNARD AND CHAS. R. THAYER, OF BOSTON, MASS.

IMPROVEMENT IN COMPOSITIONS FOR PRINTING AND COPYING INKS.

Specification forming part of Letters Patent No. 38,008, dated March 24, 1863.

,To all whom it may concern:

Be it known that we, JOHN UNDERWOOD and FREDERIC VALENTINE BURT, of the city of London, England, have invented a new and useful or Improved Manufacture of Ink for Printing and Copying; and we do hereby declare the same to be fully described in the following specification.

The object we have had in view in making our invention has been to produce an ink which not only can be used for printing on paper with types, but will enable copies of the impressions so made with it to be readily taken on paper by the common method of copying written letters orpapers by the use of moisture and a letter-press. The great advantage of such an ink will be apparent when it is considered that bill or invoice headings, leases, and other matter may be printed in the forms of what are usually termed blanksffor the use of merchants, factors, railway corporations, telegraph companies, &:c., and after the spaces in such blanks may have been written on, or figures, letters, words, or other devices been written or made in ordinary copying-ink thereon, one or more copies of the wliole--viz., both printing and writing-wan be taken by the ordinary process of letter-copying.

Common printing-inks, or such as are used for book, newspaper, or lithographic work,-will not copy in a letter-copying press, owing to the unctuous and resinous matters of which such inks are usually made. It has therefore been our purpose to combine with some of the principal ingredients used in the manufacture of writing-ink some one or more of those employed in the manufacture of such printingink, and thereby produce a composition or new or improved ink which could only be used for printing with types, but subsequently be capable of producing impressions or copies in a common merchants letter-press and by pressure and moisture.

We are fully aware that it is not new to use nut-galls, sulphate of iron, mucilaginous and saccharine matters, and various pigments in the composition of various writing-inks. We are also aware that it is not new to employ alkalies, oils, and resins in the making of printing-inks, and consequently we lay no claim to the invention of employment of any or all of such matters as heretofore used.

The nature of our composition or compositions will hefound to consist in the combination of a saponaceous material or compound with certain matters used in making writing inks or fluids, or with such and others employed in the manufacture of printing-inks.

The use of soap or the saponaceous material in question in connection with others, as set forth, we have found specially advantageous in obtaining good impressions by moisture and pressure, and also in making the compound to be used for printing with types.

To produce a printing and copying ink of the nature described, we may proceed as follows, viz: Take of nut-galls, fourteen pounds; sulphate of iron, six pounds; gum senegal, twelvepounds; treacle,sixpounds; soap,three pounds; lamp black, six pounds; Prussian blue, three pounds, and filtered rain-water, fifteen imperial gallons. The nntgalls should be first bruised, and subsequently be boiled for three hours (more or less) in one-half the abovenamed quantity of water, after which the clear liquid should be drawn 0d. The gum-senegal and the sulphate of iron should be separately dissolved in the remainder of the water, after which the solution should be mixed with the decoction of nut-gall and exposed for about twen ty-one days to the atmosphere, after which the supernatant liquid should be separated from the deposited matters and sediment. The trcacle and soap may next be added to such liquid, after which the whole should by means of a water bath be evaporated nearly to the consistency of ordinary printing-ink, and should have the lamp-back and Prussian blue stirred into it.

The above ingredients will form a black ink; but should an ink of a different color be required some other pigment or coloring-matter must be substituted for the lamp-black and Prussian blue, or what may produce or aid in producing black color.

The following formula will also suflice for the production of an excellent printing and copying ink: Take twelve pounds of nut-galls and six pounds of sulphite of iron. Bruise the nutgalls very fine and boil them, in twelve gallons of water for about forty-eight hours, adding water from time to time to make up for the loss by evaporation. Next add to the decoetion the sulphite of iron previously dissolved in three gallons of water. Expose the mixture for twenty-one days (more or less) to the atmosphere, and afterward strain it through a cloth, and subsequently filter it through filtering-paper. To the clear liquid thus obtained, and in a state ofebnllition, add fluid caustic potash until the solution will impart to red litmus-paper, when dippedinit,abluecolor. Finallyfiltertheliquid and evaporate it by a water bath to the consistency of a druggists ordinary extract. Next take of the liquid so prepared twelve ounces; of soft soap six ounces; subcarbonate of potash, two pounds; distilled water, five and onehalf imperial pints; powdered gum-tragacan th, four ounces; powdered gum arable, one and one-half pounds; treacle, two pounds; spiritblack, one pound. Mix the tragacauth and gum-arabic thoroughly together and add to them two pints of the distilled water and the twelve ounces of the prepared liquid previously combined with one pint of distilled water. Havin g incorporated all thoroughly, next stir into them the treacle. Afterward boil together the soft soap and one pound of subearbonate of potash in a pint of distilled water and add this to the mixture, being careful to stir the whole together and to gradually add small quantities of theremainingpound of snbcarbonate of potash dissolved in the remaining half or part of water. Next grind the spirit-black with the whole, so as to incorporate them together.

Ink thus manufactured, after having been deposited on paper by types, will dry thereon upon being exposed to a warm and dry atmosphere. t

When it may be desirable to obtain impressions from the imprints a damper or'moist surface (whether of paper or other material) suitable for receiving the intended offset or offsets 7 should be laid upon the printed surface and the 

